In many applications in the fluid field, in particular for cooling vehicle heat engines, thermostatic valves are used to regulate the flow of a fluid, i.e., to distribute this incoming fluid in different flow pathways, based on the temperature of that fluid. These valves are said to be thermostatic inasmuch as the movement of their inner shutter(s) is controlled by a thermostatic element, i.e., an element that comprises a body, containing a thermodilatable material, and a piston, submerged in this thermodilatable material, the body and the piston being movable relative to one another in translation along the longitudinal axis of the piston. A thermodilatable material being one that can expand with an increase in temperature.
The invention more specifically examines three-way valves, which distribute a fluid inlet between two fluid outlets or which supply a fluid outlet from two fluid inlets. These three-way valves are typically used to regulate the flow of a cooling fluid with respect to both an engine to be cooled by this fluid and a heat exchanger, in particular a radiator, cooling this fluid: when the fluid has an excessively high temperature at the valve, the latter sends it to the exchanger to be cooled therein before being sent to the engine to be cooled, then returned to the valve, whereas when the temperature of the fluid is low enough at the valve, the latter sends the fluid directly to the engine, from which it is returned to the valve, via a bypass channel not passing through the exchanger. To that end, the valve includes a main valve, which commands the flow of the fluid with respect to the heat exchanger, and a bypass valve, which commands the flow of the fluid in the aforementioned bypass. EP-A-1,936,141 and US-A-2005/001044 provide examples of this.
The invention examines valves whereof the same thermostatic element actuates, inversely, the main valve and the bypass valve. In this case, it is known that the moving part of the thermostatic element is securely connected to a same piece of equipment including the shutter of the main valve and the shutter of the bypass valve, subject to the interposition of a return spring between this piece of equipment and a bracket, which, during use, is securely connected to a casing or a similar part, fastened to the valve casing to which the stationary part of the thermostatic element is fixedly connected. By further providing that the piece of equipment and the bracket, which, when the valve is in use, are movable relative to one another to open and close the bypass valve, are permanently retained to one another so as to keep the return spring compressed between them, the unit formed by the assembly of the thermostatic element, the piece of equipment, the bracket and the return spring constitutes an integrated device with a pre-stressed spring: such a spring has the advantage of being able to be mounted in a single piece on the aforementioned casings, in particular without using tooling dedicated to compressing the return spring. DE-U-20 2010 017 837 provides one example of this.
The integration of these devices nevertheless has the drawback of causing them not to be very configurable, inasmuch as the design and sizing of such a device are specific to the assembly environment of this device. In particular, due to its design, the aforementioned piece of equipment freezes both the diameter of the shutter of the main valve and the diameter of the shutter of the bypass valve, which therefore limits the possibilities for using pre-existing thermostatic elements, with various shapes and sizes, and which requires the shape of the bracket to be adapted in a specifically dedicated manner. The cost of manufacturing and restocking these devices is affected as a result.